From 878beb16ad10d1e1e44d51f3841d44a6836bb4e9 Mon Sep 17 00:00:00 2001
From: dec05eba <dec05eba@protonmail.com>
Date: Mon, 19 Oct 2020 14:56:53 +0200
Subject: Fix threading crash (assigning to a new thread before the thread has
 died), caching of images smaller than thumbnail target size

---
 include/ImageViewer.hpp  |  1 +
 src/AsyncImageLoader.cpp | 16 +++++++++++-----
 src/ImageViewer.cpp      |  9 ++++++++-
 3 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/include/ImageViewer.hpp b/include/ImageViewer.hpp
index 2cf3ac2..ea53558 100644
--- a/include/ImageViewer.hpp
+++ b/include/ImageViewer.hpp
@@ -47,6 +47,7 @@ namespace QuickMedia {
     class ImageViewer {
     public:
         ImageViewer(MangaImagesPage *manga_images_page, const std::string &content_title, const std::string &chapter_title, int current_page, const Path &chapter_cache_dir, sf::Font *font);
+        ~ImageViewer();
         ImageViewerAction draw(sf::RenderWindow &window);
         // Returns page as 1 indexed
         int get_focused_page() const;
diff --git a/src/AsyncImageLoader.cpp b/src/AsyncImageLoader.cpp
index 2f0f869..05c6a7e 100644
--- a/src/AsyncImageLoader.cpp
+++ b/src/AsyncImageLoader.cpp
@@ -103,7 +103,7 @@ namespace QuickMedia {
     }
 
     AsyncImageLoader::AsyncImageLoader() {
-        for(size_t i = 0; i < NUM_IMAGE_LOAD_THREADS; ++i) {
+        for(int i = 0; i < NUM_IMAGE_LOAD_THREADS; ++i) {
             loading_image[i] = false;
         }
 
@@ -147,6 +147,12 @@ namespace QuickMedia {
             load_image_cv.notify_one();
         }
         load_image_thread.join();
+
+        // TODO: Find a way to kill the threads instead. We need to do this right now because creating a new thread before the last one has died causes a crash
+        for(size_t i = 0; i < NUM_IMAGE_LOAD_THREADS; ++i) {
+            if(download_image_thread[i].joinable())
+                download_image_thread[i].join();
+        }
     }
 
     void AsyncImageLoader::load_thumbnail(const std::string &url, bool local, sf::Vector2i resize_target_size, bool use_tor, std::shared_ptr<ThumbnailData> thumbnail_data) {
@@ -182,6 +188,8 @@ namespace QuickMedia {
 
         loading_image[free_index] = true;
         thumbnail_data->loading_state = LoadingState::LOADING;
+        if(download_image_thread[free_index].joinable())
+            download_image_thread[free_index].join();
 
         // TODO: Keep the thread running and use conditional variable instead to sleep until a new image should be loaded. Same in ImageViewer.
         download_image_thread[free_index] = std::thread([this, free_index, thumbnail_path, url, local, resize_target_size, thumbnail_data, use_tor]() mutable {
@@ -199,9 +207,8 @@ namespace QuickMedia {
                         return;
                     }
                 } else {
-                    Path download_path = thumbnail_path;
-                    download_path.append(".orig");
-                    if(download_to_file(url, download_path.data, {}, use_tor, true) != DownloadResult::OK || !thumbnail_data->image->loadFromFile(download_path.data)) {
+                    // Use the same path as the thumbnail path, since it wont be overwritten if the image is smaller than the thumbnail target size
+                    if(download_to_file(url, thumbnail_path.data, {}, use_tor, true) != DownloadResult::OK || !thumbnail_data->image->loadFromFile(thumbnail_path.data)) {
                         thumbnail_data->loading_state = LoadingState::FINISHED_LOADING;
                         loading_image[free_index] = false;
                         return;
@@ -216,7 +223,6 @@ namespace QuickMedia {
             loading_image[free_index] = false;
             return;
         });
-        download_image_thread[free_index].detach();
     }
 
     int AsyncImageLoader::get_free_load_index() const {
diff --git a/src/ImageViewer.cpp b/src/ImageViewer.cpp
index a8e6041..fc7b758 100644
--- a/src/ImageViewer.cpp
+++ b/src/ImageViewer.cpp
@@ -35,11 +35,19 @@ namespace QuickMedia {
         has_size_vertical_cursor = size_vertical_cursor.loadFromSystem(sf::Cursor::SizeVertical);
     }
 
+    ImageViewer::~ImageViewer() {
+        // TODO: Remove
+        if(image_loader_thread.joinable())
+            image_loader_thread.join();
+    }
+
     void ImageViewer::load_image_async(const Path &path, std::shared_ptr<ImageData> image_data) {
         image_data->image_status = ImageStatus::LOADING;
         image_data->texture.setSmooth(true);
         assert(!loading_image);
         loading_image = true;
+        if(image_loader_thread.joinable())
+            image_loader_thread.join();
         image_loader_thread = std::thread([this, image_data, path]() mutable {
             auto image = std::make_unique<sf::Image>();
             if(image->loadFromFile(path.data)) {
@@ -50,7 +58,6 @@ namespace QuickMedia {
             }
             loading_image = false;
         });
-        image_loader_thread.detach();
     }
 
     bool ImageViewer::render_page(sf::RenderWindow &window, int page, double offset_y) {
-- 
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